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Pacini G, Ieronymaki M, Nuti F, Sabatino G, Larregola M, Aharoni R, Papini AM, Rovero P. Epitope mapping of anti-myelin oligodendrocyte glycoprotein (MOG) antibodies in a mouse model of multiple sclerosis: microwave-assisted synthesis of the peptide antigens and ELISA screening. J Pept Sci 2015; 22:52-8. [PMID: 26663200 DOI: 10.1002/psc.2839] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 10/28/2015] [Accepted: 10/28/2015] [Indexed: 01/06/2023]
Abstract
The role of pathologic auto-antibodies against myelin oligodendrocyte glycoprotein (MOG) in multiple sclerosis is a highly controversial matter. As the use of animal models may enable to unravel the molecular mechanisms of the human disorder, numerous studies on multiple sclerosis are carried out using experimental autoimmune encephalomyelitis (EAE). In particular, the most extensively used EAE model is obtained by immunizing C57BL/6 mice with the immunodominant peptide MOG(35-55). In this scenario, we analyzed the anti-MOG antibody response in this model using the recombinant refolded extracellular domain of the protein, MOG(1-117). To assess the presence of a B-cell intramolecular epitope spreading mechanism, we tested also five synthetic peptides mapping the 1-117 sequence of MOG, including MOG(35-55). For this purpose, we cloned, expressed in Escherichia coli and on-column refolded MOG(1-117), and we applied an optimized microwave-assisted solid-phase synthetic strategy to obtain the designed peptide sequences. Subsequently, we set up a solid-phase immunoenzymatic assay testing both naïve and EAE mice sera and using MOG protein and peptides as antigenic probes. The results obtained disclose an intense IgG antibody response against both the recombinant protein and the immunizing peptide, while no response was observed against the other synthetic fragments, thus excluding the presence of an intramolecular epitope spreading mechanism. Furthermore, as the properly refolded recombinant probe is able to bind antibodies with greater efficiency compared with MOG(35-55), we hypothesize the presence of both linear and conformational epitopes on MOG(35-55) sequence.
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Affiliation(s)
- Giulia Pacini
- French-Italian Interdepartmental Laboratory of Peptide and Protein Chemistry and Biology - PeptLab, Florence, Italy and Cergy-Pontoise, France.,Department NeuroFarBa, Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Via Ugo Schiff 6, Sesto Fiorentino, Florence, I-50019, Italy
| | - Matthaia Ieronymaki
- French-Italian Interdepartmental Laboratory of Peptide and Protein Chemistry and Biology - PeptLab, Florence, Italy and Cergy-Pontoise, France.,Department NeuroFarBa, Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Via Ugo Schiff 6, Sesto Fiorentino, Florence, I-50019, Italy.,Laboratoire de Chimie Biologique EA4505, University of Cergy-Pontoise, 5 mail Gay-Lussac Neuville-sur-Oise, Cergy-Pontoise, 95000, France
| | - Francesca Nuti
- French-Italian Interdepartmental Laboratory of Peptide and Protein Chemistry and Biology - PeptLab, Florence, Italy and Cergy-Pontoise, France.,Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3/13, Sesto Fiorentino, Florence, I-50019, Italy
| | - Giuseppina Sabatino
- French-Italian Interdepartmental Laboratory of Peptide and Protein Chemistry and Biology - PeptLab, Florence, Italy and Cergy-Pontoise, France.,Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3/13, Sesto Fiorentino, Florence, I-50019, Italy
| | - Maud Larregola
- French-Italian Interdepartmental Laboratory of Peptide and Protein Chemistry and Biology - PeptLab, Florence, Italy and Cergy-Pontoise, France.,Laboratoire de Chimie Biologique EA4505, University of Cergy-Pontoise, 5 mail Gay-Lussac Neuville-sur-Oise, Cergy-Pontoise, 95000, France
| | - Rina Aharoni
- Department of Immunology, The Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Anna Maria Papini
- French-Italian Interdepartmental Laboratory of Peptide and Protein Chemistry and Biology - PeptLab, Florence, Italy and Cergy-Pontoise, France.,Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3/13, Sesto Fiorentino, Florence, I-50019, Italy.,Laboratoire de Chimie Biologique EA4505, University of Cergy-Pontoise, 5 mail Gay-Lussac Neuville-sur-Oise, Cergy-Pontoise, 95000, France
| | - Paolo Rovero
- French-Italian Interdepartmental Laboratory of Peptide and Protein Chemistry and Biology - PeptLab, Florence, Italy and Cergy-Pontoise, France.,Department NeuroFarBa, Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Via Ugo Schiff 6, Sesto Fiorentino, Florence, I-50019, Italy
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Mayer MC, Meinl E. Glycoproteins as targets of autoantibodies in CNS inflammation: MOG and more. Ther Adv Neurol Disord 2013; 5:147-59. [PMID: 22590479 DOI: 10.1177/1756285611433772] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
B cells and antibodies constitute an important element in different inflammatory diseases of the central nervous system (CNS). Autoantibodies can serve as a biomarker to identify disease subgroups and may in addition contribute to the pathogenic process. One candidate autoantigen for multiple sclerosis (MS) is myelin oligodendrocyte glycoprotein (MOG). MOG is localized at the outermost surface of myelin in the CNS and has been the focus of extensive research for more than 30 years. Its role as an important autoantigen for T cells and as a target of demyelinating autoantibodies has been established in several variants of experimental autoimmune encephalomyelitis (EAE), an animal model of MS. The literature regarding antibodies to MOG in MS patients is confusing and contradictory. Recent studies, however, have described high levels of antibodies to conformationally correct MOG in pediatric acquired demyelination, both acute disseminated encephalomyelitis (ADEM) and MS. In adult MS, such antibodies are rarely found and then only at low levels. In this review, we summarize key findings from animal models and patient studies, discuss challenges in detecting anti-MOG antibodies in patients and present recent approaches to identifying new autoantigens in MS.
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Affiliation(s)
- Marie Cathrin Mayer
- Max Planck Institute of Neurobiology, Department of Neuroimmunology, Martinsried, Germany and Institute of Clinical Neuroimmunology, Ludwig-Maximilians-University, Munich, Germany
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Conformational epitopes of myelin oligodendrocyte glycoprotein are targets of potentially pathogenic antibody responses in multiple sclerosis. J Neuroinflammation 2011; 8:161. [PMID: 22093619 PMCID: PMC3238300 DOI: 10.1186/1742-2094-8-161] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Accepted: 11/17/2011] [Indexed: 12/03/2022] Open
Abstract
Background Myelin/oligodendrocyte glycoprotein (MOG) is a putative autoantigen in multiple sclerosis (MS). Establishing the pathological relevance and validity of anti-MOG antibodies as biomarkers has yielded conflicting reports mainly due to different MOG isoforms used in different studies. Because epitope specificity may be a key factor determining anti-MOG reactivity we aimed at identifying a priori immunodominant MOG epitopes by monoclonal antibodies (mAbs) and at assessing clinical relevance of these epitopes in MS. Methods Sera of 325 MS patients, 69 patients with clinically isolated syndrome and 164 healthy controls were assayed by quantitative, high-throughput ELISA for reactivity to 3 different MOG isoforms, and quantitative titers correlated with clinical characteristics. mAbs defined unique immunodominant epitopes distinct to each of the isoforms. Results In the majority of human samples anti-MOG levels were skewed towards low titers. However, in 8.2% of samples high-titer anti-MOG antibodies were identified. In contrast to anti-MOG reactivity observed in a mouse model of MS, in patients with MS these never reacted with ubiquitously exposed epitopes. Moreover, in patients with relapsing-remitting MS high-titer anti-MOG IgG correlated with disability (EDSS; Spearman r = 0.574; p = 0.025). Conclusions Thus high-titer reactivity likely represents high-affinity antibodies against pathologically relevant MOG epitopes, that are only present in a small proportion of patients with MS. Our study provides valuable information about requirements of anti-MOG reactivity for being regarded as a prognostic biomarker in a subtype of MS.
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Selmi C, Maria Papini A, Pugliese P, Claudia Alcaro M, Gershwin ME. Environmental pathways to autoimmune diseases: the cases of primary biliary cirrhosis and multiple sclerosis. Arch Med Sci 2011; 7:368-80. [PMID: 22295019 PMCID: PMC3258751 DOI: 10.5114/aoms.2011.23398] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Revised: 05/15/2011] [Accepted: 05/19/2011] [Indexed: 12/21/2022] Open
Abstract
The pathways leading to autoimmunity remain enigmatic despite numerous lines of experimental inquiry and epidemiological evidence. The mechanisms leading to the initiation and perpetuation of specific diseases such as primary biliary cirrhosis (PBC) or multiple sclerosis (MS) remain largely enigmatic, although it is established that a combination of genetic predisposition and environmental stimulation is required. The growing number of genome-wide association studies and the largely incomplete concordance for autoimmune diseases in monozygotic twins concur to support the role of the environment (including infectious agents and chemicals) in the breakdown of tolerance leading to autoimmunity through different mechanisms. In the present article we illustrate the current hypotheses related to an environmental impact on the onset of PBC and MS as two representative conditions investigated with complementary approaches. Indeed, while a role of post-translational antigen modifications has been proposed for MS, this field remain unexplored in PBC where, conversely, most evidence is gathered from geoepidemiology and experimental data on xenobiotics or infectious agents.
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Affiliation(s)
- Carlo Selmi
- Department of Medicine and Autoimmunity and Metabolism Unit, IRCCS Istituto Clinico Humanitas, Rozzano, Milan, Italy
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